Rolling train for the rolling of wire and light steel sections

ABSTRACT

A rolling line for wire and light sections in which the horizonal and vertical rolls are provided in a common stand, one upstream of the other and the axis planes are spaced in the rolling direction, the spacing is adjustable and the spacing can be set for a particular rolling operation. The grooves of the upstream pair of rolls can deform the original section of the workpiece of an intermediate shape which is restored by the downstream pair of rolls with a reduced dimension.

FIELD OF THE INVENTION

[0001] Our present invention relates to a rolling train for the rolling of wire and light sections, usually of steel or iron, in which prerolling and intermediate rolling stages precede the finishing or finish-rolling stage and the prerolling and intermediate rolling stages comprise alternating horizontal and vertical roll pairs in succession.

BACKGROUND OF THE INVENTION

[0002] In the prerolling and intermediate rolling lines or the prerolling and intermediate rolling segments of the entire wire or light section rolling train, the bar-shaped or billet-shaped workpiece is rolled in a more or less large number of roll stands which are spaced apart from one another and respectively contain horizontal and vertical roll pairs with a relatively large reduction in cross section per roll stand, i.e. from roll stand to roll stand to outer dimensions which are only slightly greater that the outer dimensions of the finished product.

[0003] The intermediate rolled product from the intermediate rolling segment or line, with the resulting cross section and dimensions, is then fed to the finishing or dimensioning rolling line or segment of the wire or light section rolling train. The rolls of the finishing or dimensioning rolling line stand have a caliber (roll-defined orifice or lumen cross section) which is intended to effect the cross sectional correction and final dimensioning or sizing of the intermediate rolled product.

[0004] Each of the rolling stand in the prerolling and intermediate rolling lines or the prerolling and intermediate rolling segments of the wire or light section rolling train generally has its own drive and between the individual rolling stands guides are required for positioning and/or supporting the workpiece strand. These guides or supports may be roller conveyors. Wire or light section rolling trains of this type are expensive because of the numerous components required, occupy a large amount of space and have correspondingly large operating, service and maintenance costs.

[0005] From EP 0 768 124 A2 and 0 549 896 A1 rolling trains are known for the dimensional rolling of wire in which the rolled product from an intermediate stage is subjected to final or finish rolling and is there rolled to its final dimensions. In the final dimension-imparting rolling stage, one or two rolling stands can have horizontal roll pair and a vertical roll pair in succession and one close behind the other and the roll pairs so arranged that their vertical axis planes can be shifted in the rolling direction relative to one another and then fixed at a set spacing.

OBJECTS OF THE INVENTION

[0006] It is therefore the principal object of the present invention to provide a rolling line or train for wire rod and light sections which can utilize a comparatively small number of roll pairs or roll stands and, with a reduced capital cost, nevertheless provide for improved control of the rolling operation and the shaping of the workpiece.

[0007] It is also an object of the invention to provide an improved method of operating a rolling train or rolling line for the rolling of wire, rod and light sections of steel or iron whereby the cost of the process can be reduced while the control can be improved and, indeed, advantages of the prior art system can be retained while the capital cost is lowered.

[0008] Still another object of this invention is to provide an improved rolling train or rolling line for wire, rod and light section and a method of operating it, whereby drawbacks of earlier systems are avoided.

SUMMARY OF THE INVENTION

[0009] These objects are attained, in accordance with the invention in a rolling train for wire, rod and light sections of steel and iron which comprises:

[0010] a rolling path along which a metallic workpiece is rolled to a final shape and dimensions from an initial shape and dimensions;

[0011] a prerolling stretch at an upstream location along the path and including at least one prerolling stage having at least one succession of roll stands and including horizontal roll pairs alternating with vertical roll pairs;

[0012] an intermediate rolling stretch downstream of the prerolling stretch along the path and including at least one intermediate stage having at least one succession of roll stands and including horizontal roll pairs alternating with vertical roll pairs; and

[0013] a final rolling stretch for final dimension and shape rolling of the workpiece downstream of the intermediate rolling stretch,

[0014] at least one of the successions of roll stands comprising:

[0015] at least one common roll stand for a respective one of said horizontal roll pairs and a respective one of said vertical roll pairs,

[0016] a drive connected to the common rolls of the horizontal roll stand of the at least one of the successions, and

[0017] a mechanism for controlling a spacing between vertical planes of axes of the horizontal rolls and axes of vertical rolls of the common roll stand.

[0018] An auxiliary drive capable of being switched on and off can be connected to drive the vertical rolls and can be coupled to the drive for the horizontal rolls of the common roll stand. Of course several of such common roll stands can be provided in each of said successions and in both the prerolling and intermediate rolling stretches.

[0019] The method of operating the roll train can comprise the steps of:

[0020] passing a metallic workpiece along a rolling path in which the metallic workpiece is rolled to a final shape and dimensions from an initial shape and dimensions;

[0021] rolling the workpiece in a prerolling stretch at an upstream location along the path and including at least one prerolling stage having at least one succession of roll stands including horizontal roll pairs alternating with vertical roll pairs;

[0022] thereafter rolling the workpiece in an intermediate rolling stretch downstream of the prerolling stretch along the path and including at least one intermediate stage having at least one succession of roll stands including horizontal roll pairs alternating with vertical roll pairs; and

[0023] finally rolling the workpiece in a final rolling stretch for final dimension and shape rolling of the workpiece downstream of the intermediate rolling stretch,

[0024] at least one of the successions of two roll stands comprising:

[0025] at least one common roll stand of at least one of said successions having a respective one of said horizontal roll pairs and a respective one of said vertical roll pairs,

[0026] a drive connected to horizontal rolls of the horizontal roll pair of the common stand, and

[0027] a mechanism for controlling a spacing between vertical planes of axes of the horizontal rolls of the horizontal roll pair and axes of vertical rolls of the vertical roll pair of the common stand,

[0028] the workpiece passing from a caliber defined by the rolls of said common stand directly into a caliber defined by the vertical rolls of the common stand so that said vertical rolls engage a length of the workpiece under compression by the horizontal rolls of the common stand.

[0029] Where the first of the two roller pairs in a given stand is a vertical roller pair, and the workpiece can be rolled in the first of the two roller pairs from a circular cross section to a horizontally elongated oval cross section and then rolled in the grooves of the second of the two roller pairs again to a circular cross section.

[0030] A distance between vertical-axis planes of the two roller pairs is selected to that the grooves of the vertical roller pair encompass a still compressed length of the workpiece emerging from the grooves of the horizontal roller pair.

[0031] The invention thus utilizes mill stands which include a driven horizontal roll pair and a vertical roll pair which precedes or, preferably, follows the horizontal roll pair in the rolling direction, i.e. the direction of travel of the workpiece along the rolled line. In accordance with the invention, the vertical axis planes of the two roll pairs are offset from one another in the rolling direction, i.e. are spaced apart, the spacing is adjustable and the adjusted spacing can be set or fixed for the particular rolling purpose. The vertical roll pair can be provided with an auxiliary drive which can be turned on and off as noted.

[0032] This rolling line is so operated that the workpiece receives an intermediate cross section in the first of the two roll pairs as defined by the grooves of the rolls thereof and immediately thereafter this workpiece cross section is transformed in the grooves of the section roll pair to a shape corresponding to the inlet shape of the workpiece to the first roll pair but with reduced dimensions.

[0033] When, for example, the vertical roll pair precedes the horizontal roll pair, the circular cross section of the workpiece entering the grooves of the vertical roll pair is transformed into a horizontal oval in that vertical roll pair and immediately thereafter is converted back to a circular cross section in the horizontal roll pair. Conversely, where the horizontal roll pair precedes the vertical roll pair, the circular workpiece is transformed into a workpiece of oval cross section in the grooves of the horizontal rolls and is then transformed back to a circular cross section in the grooves of the vertical roll but with a reduced diameter.

[0034] According to a feature of the invention, the spacing of the vertical axis plane of the vertical roll from the vertical axis plane of the horizontal roll is so dimensioned that the grooves of the vertical roll encompass the region at which the compressed length of the rolled wire emerges from the grooves of the horizontal roll. The rolling method of the invention, apart from the groove sequence described, can also encompass groove sequences of square-square section, rectangular-square section, square-rectangular section, diamond-diamond section, diamond section-square section and square-diamond section.

BRIEF DESCRIPTION OF THE DRAWING

[0035] The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

[0036]FIG. 1 is a side view diagrammatically illustrating the relationship between the upstream horizonal and downstream vertical roll in accordance with the invention;

[0037]FIG. 2 is a partial section taken along the line II-II of FIG. 1 and

[0038]FIG. 3 is a side view illustrating a rolling line according to the invention.

SPECIFIC DESCRIPTION

[0039] Referring first to FIG. 3, it can be seen that a rolling line for rolling a wire, rod or light section workpiece 10 in the rolling direction represented by the arrow 11 can comprise a preliminary stage 12, also referred to as a prerolling stage, an intermediate stage 13 and a final stage 14. The latter may utilize a double universal stand finishing roll system of the type described and illustrated at EP 0 549 896.

[0040] The invention applies to the preliminary stage 12 and/or the intermediate stage 13, each of which can have one or more stands (usually a plurality of stands), each with a pair of horizontal rolls 15, 16 and a pair of vertical rolls 17 where the horizonal rolls precede the vertical roll or a pair of vertical rolls 18 precede the horizontal rolls 19 and 20. The stands are designated at I and II and each has both a pair of horizontal rolls and a pair of vertical rolls.

[0041] In FIG. 3 the spacing between the vertical axis plane of the two roll pairs of each stand has been increased for clarity. The preferred relationship is that which is apparent from FIG. 1, i.e. an arrangement in which the still compressed length of the workpiece strand from the caliber of the horizontal roll pair is engaged in the caliber of the vertical roll pair of the same stand.

[0042] Each of the rolls has a groove 21 shown only for the roll 17 in FIG. 3. The grooves of the two rolls of each pair may define a “caliber” with a circular cross section or oval cross section as will be apparent from FIGS. 1 and 2. The horizontal rails 15, 16 or 19, 20 may be directly driven by drives 22 and 23 and the vertical rolls may be driven off these main drives by auxiliary drives 24 and 25. In addition, shifters 26 and 27 can be provided to set the spacing along the rolling line between the vertical axis plane of the horizontal and vertical rolls.

[0043] Turning now to FIGS. 1 and 2 from which this relationship will become more clear, it can be seen that the double stand for horizontal and vertical rolls which has not been illustrated can have the horizontal rolls H1 and H2 with their axes AH1 and AH2 journaled therein so that these axes lie in a vertical axis plane VEH.

[0044] In FIG. 1, the roll direction is represented at WR and upstream of the horizontal roll, a pair of vertical rolls V1, V2 is journaled on this stand with their axes (one of which is shown at AV1) lying in the vertical axis plane VEV. The spacing between these vertical axis planes, i.e. the offset in the rolling direction is represented at L and can be adjusted and set by the respective shifter 26 or 27. As will be apparent from FIG. 2, the round cross section VP entering the grooves of the upstream pair of rolls is transformed in this upstream pair of rolls to the intermediate oval cross section ZO and then in the grooves of the downstream pair of rolls to the finished circular cross section FR.

[0045] As FIG. 1 shows, the rolls can be so close that the downstream roll pair engages the workpiece while it is still encompassed in the grooves of the upstream pair of rolls.

[0046] For a double stand of the type used with the invention only one main drive is required since the power can be drawn therefrom for the other pair of rolls via the auxiliary or power takeoff drive. Supports for the workpiece between pairs of rolls are eliminated along with the cost and separate main drives, for example, for the vertical rolls are not necessary either.

[0047] The invention, whereby a common stand for horizontal and vertical roll pairs is provided as described in the intermediate stretch, has been found to allow the number of roll stands of the intermediate stretch to be reduced by half and to eliminate the need for a corresponding number of roll drives. The space required for the rolling train is correspondingly reduced as is the need for guide units between roll stands. 

We claim:
 1. A rolling train for wire, rod and light sections and comprising: a rolling path along which a metallic workpiece is rolled to a final shape and dimensions from an initial shape and dimensions; a prerolling stretch at an upstream location along said path and including at least one prerolling stage having at least one succession of horizontal and vertical roll pairs alternating with one another; an intermediate rolling stretch downstream of said prerolling stretch along said path and including at least one intermediate stage having at least one succession horizontal and vertical roll pairs alternating with one another; and a final rolling stretch for final dimension and shape rolling of said workpiece downstream of said intermediate rolling stretch, at least one of said successions of two roll stands comprising: a common roll stand receiving both a horizontal roll pair and a vertical roll pair, a drive connected to horizontal rolls of the horizontal roll pair of said common roll stand, and a mechanism for controlling a spacing between vertical planes of axes of said horizontal rolls and axes of vertical rolls of the common roll stand.
 2. The rolling train defined in claim 1, further comprising an auxiliary drive capable of being switched on and off connected to drive said vertical rolls of the common roll stand.
 3. The rolling train defined in claim 1 wherein said auxiliary drive is coupled to the drive of said horizontal rolls.
 4. The rolling train defined in claim 1 wherein said common roll stand is in said intermediate stretch.
 5. The rolling train defined in claim 1 wherein said horizontal rolling stand precedes said vertical rolling stand along said path in said at least one of said successions.
 6. The rolling train defined in claim 1 wherein said vertical roll pair of said stand engages said workpiece as it emerges under pressure from the caliber of a pair of said stand.
 7. A method of operating a rolling train for wire, rod and light sections, comprising the steps of: passing a metallic workpiece along a rolling path in which the metallic workpiece is rolled to a final shape and dimensions from an initial shape and dimensions; rolling said workpiece in a prerolling stretch at an upstream location along said path and including at least one prerolling stage having at least one succession of a horizontal roll pair and a vertical roll pair alternating with one another; thereafter rolling said workpiece in an intermediate rolling stretch downstream of said prerolling stretch along said path and including at least one intermediate stage having at least one succession of a horizontal roll pair and a vertical roll pair alternating with one another; and finally rolling said workpiece in a final rolling stretch for final dimension and shape rolling of said workpiece downstream of said intermediate rolling stretch, at least one of said successions of two roll stands comprising: a common drive stand for both a horizontal roll pair and a vertical roll pair, a drive connected to horizontal rolls of the horizontal roll pair of said stand, and a mechanism for controlling a spacing between vertical planes of axes of said horizontal rolls and axes of vertical rolls of said stand, the workpiece exiting grooves of a first of the roller pairs of the stand being engaged directly and while still under the pressure of the first of the roller pairs in grooves of a second of said two roller pairs of the stand.
 8. The method defined in claim 7 wherein the first of said two roller pairs is a horizontal pair. 